You can rent games from the library. And if they're on a play station 4, it could be one they've had for a very long time. Plus they said they allocate $75/month in misc. It may very well be one game they play all the time, so they only needed to buy it the one time. Or for a game like Destiny 2 that has new DLC type releases every ~3-4 or so months, it's easy to squirrel away money to cover any new purchases.